This invention relates generally to satellite communication systems and more particularly to laser satellite communication systems wherein data is transmitted to, and/or from a satellite using lasers.
As is known in the art information is sometimes transmitted between various locations on the earth by routes which include satellites. More particularly, in the routing process, information may be transmitted from a ground station along the route to a satellite. The receiving satellite may, in some arrangements, retransmit the information to a remote ground station along the route. In other arrangements, the receiving satellite may be retransmit the information directly to another satellite along the route, which, in turn may itself retransmit to another satellite, or to a remote ground station. The transmission path, or data link, directly between a pair of satellites is sometimes referred to as an inter-satellite cross link in the routing process. While transmission of data between the ground station and satellite is typically by radio frequency (RF) energy, the use of laser energy, at least for communication between satellites (i.e., for the inter satellite cross links) offers distinct advantages over radio frequency (RF) systems, particularly for satellite cross links. These advantages include the potential for a great reduction in weight, power for a given data rate, lack of optical spectral congestion and frequency allocation requirements, immunity to electromagnetic interference, co-located transmitters and RF jammers.